1. Field of the Invention
The present invention relates generally to stick prevention apparatus for protecting medical personnel from injury. More particularly, the present invention relates to tip protection devices having internal elements which prevent a retracted needle from reinserting therethrough and a method for forming the elements.
2. Description of Prior Art
Medical care of individuals in hospitals, clinics, and other health care facilities often includes the taking of blood samples, intravenous supplying of medication, and the introduction or removal of other fluids via cannulae, needles, or syringes. The present medical environment, in which there exist diseases, for example Acquired Immune Deficiency Syndrome, AIDS, for which there are no cures, and which are transmitted via blood to blood contact, has raised concerns relating to the potential for contaminated "needle sticks".
A wide variety of devices have been provided in the prior art for prevention against accidental contaminated "needle sticks". For example, U.S. Pat. No. 5,215,528 to Purdy et al. (hereinafter Purdy) teaches an assembly for introducing a catheter into a blood vessel, wherein there is provided a tip cover. The tip cover of the Purdy device is provided with an elastically deforming L-shaped member which remains in a deformed state until the cannula is drawn back into the cover. Once retracted, the L-shaped member springs into a position to prevent reemergence of the needle. Manual repositioning of the L-shaped member is necessary to permit the cannula to reemerge from the cover.
U.S. Pat. No. 4,826,490 to Byrne et al. (hereinafter Byrne) teaches a safety cover and syringe assembly wherein an external cylindrical sleeve, through which the cannula extends, is slidably mounted to a track on the external surface of the syringe. Sliding the external cylindrical sleeve relative to the cannula and the syringe, such that the cannula is fully retracted into the sleeve, causes a locking mechanism to engage between the syringe and the sleeve so that the cannula may not be advanced out of the sleeve without disengagement of the locking elements by a user.
U.S. Pat. No. 5,127,905 to Lemieux teaches a protection cap, which is similar to the device disclosed by Purdy, as described above. In the Lemieux device an externally mounted rotating L-shaped lever is disposed along the axis of the cover, manual actuation of which by a user once the cannula is retracted prevents the cannula from reemerging from the cover. Manual retraction of the external L-shaped lever from the path of the cannula permits the cannula to reemerge.
The above described devices each include means for preventing "needle sticks" by interfering with the exposure of a cannula once it is retracted into a cover. In each case, however, the cannula may reemerge by removal or disengagement of the preventing means. In the devices disclosed by Purdy and Lemieux a user may retract the L-shaped element; in Byrne, the device includes a simple means for disengaging the locking elements. It is of considerable concern for users of such devices that, if a means for disengaging the retaining element is provided, random forces may expose the contaminated cannula, thus presenting a danger to medical personnel. This concern is applicable to the variety of "needle stick" prevention devices which include externally mounted prevention means.
It is, therefore, a principal object of the present invention to provide a needle cover which includes an element or elements which prevent exposure of a contaminated cannula.
It is further an object of the present invention to provide a needle cover which cannot be compromised, whereby the cannula may not reemerge therethrough, by application of random environmental forces.
It is further an object of the present invention to provide a needle cover which is more reliable in its safety aspects.
Other objects and advantages of the invention will be more fully apparent from the ensuing disclosure and appended claims.